1. Field of the Invention
The invention relates to waterwheel-driven generating assemblies. More particularly, the invention relates to waterwheel-driven generating assemblies adapted for application at locations without an existing dam. The invention further relates to a waterwheel-driven generating unit operating in an overshot or pitchback mode and including booster jets directing streams of high pressure water against the buckets of the wheel near their lowest point.
2. Description of the Prior Art
This invention pertains, in general, to waterwheels containing a speed-increaser gear unit and an electric generator internally contained within the waterwheel. One waterwheel-drive generating unit known to the public is disclosed in the inventors' own U.S. Pat. No. 5,440,175, entitled "Waterwheel-Driven Generating Unit", to Mayo, Jr. et al., which is incorporated herein by reference.
At present and in the recent past, hydroelectric installations using low-head dam sites, such as those typically less than 15 feet when measured vertically from headwater to tailwater, have generally been unable to economically develop commercial power. The limited number of installations of this type which have been developed had either a subsidy, special power rates, very unusual site conditions, or proved to be economic failures. The hydraulic turbines currently being manufactured are usually custom-designed and are very expensive per unit of power output due to their complex designs which require such items as trash racks, flume or penstock, intake gate, speed-increaser and generator, powerhouse, tailrace and possibly other auxiliary equipment. Existing dams are typically most economical to develop but they also require either an opening through or around the dam or a syphon intake. Each of these items adds substantially to the cost.
As the inventors' own U.S. Pat. No. 5,440,175 shows, attempts have been made to overcome the limitations of the prior art as discussed above. However, no solution has been provided to address the use of waterwheel-driven generating assemblies at locations having no existing dam. The present invention provides a solution to the need for waterwheel-driven generating units at locations having no existing dam.